Julian Prather
AICE Marine Science
Glenn
5th Period
Biodiversity Checkpoint Assignment 2
1. What is a keystone species? Define it.
A keystone species is an important species within an ecosystem; a species that the
ecosystem typically has to rely on for stability.
2. Why do you feel that they are important to an ecosystem?
Keystone species usually keep the ecosystem in check by ensuring that the way it
functions stays the same, which makes them very important for the maintenance of
ecosystems. For example, a keystone species in the coral reef ecosystem is the coral,
as without them, the ecosystem itself would not be able to exist.
3. What were some of the examples we talked about in regards to keystone species?
Predators in the Sahara desert, the whales that cause whale falls, tube worms, and
much more.
4. 5 things:
- There roles in the ecosystem make or break that ecosystem and are studied for
years
- Keystone species typically do not have small niches. A lot of keystone species
are omnivores or carnivores that consume a lot.
- It is most common for keystone species to be at the very top or at the bottom of
food chains.
Shoaling
1. What is shoaling?
- Shoaling is when a group of organisms in the water stay together for either social
or productive reasons.
2. What are the benefits of shoaling?
- Shoals protect the fish against predators who may be scared
- Shoals allow for easier finding of food
- Higher mating potential
3. What are the cons of shoaling for some organisms?
- Disease is a high risk and can spread easy
- Bigger predators are attracted more easily
Stable vs Unstable Environments
1. From the notes and the discussion that we had in class. Describe why biodiversity is
higher in stable environments and lower in unstable or extreme environments. Your
response should be at least 150-200 words.
Environments and ecosystems rely on having a stable food chain. Without one, the ecosystem
will collapse. An unstable environment is one where this food chain can change a lot, and these
environments tend to not last long at all in comparison to stable environments. Unstable
environments are also usually the developing form of stable environments, as lots of the species
in unstable environments are competing with each other. This is because they are fighting for
the same resources. This typically causes adaptation or the death of a species, which is another
thing that makes unstable environments so unstable. Not only is biodiversity lowered from
species deaths and competition, but also most unstable environments tend to be unsuitable for
most species to live in on the basic level. Lots of unstable ecosystems are unstable because
they simply have uncommon conditions that most species are not adapted to. This means that
the biodiversity will be low as species simply cannot live there. A good example of this would be
hot vents in the ocean.
Succession
1. Define it. What is it?
Succession is when the basic structure of an ecosystem changes. A good example is
when a new predator is introduced to an ecosystem, and wipes out a basic consumer.
2. There are 2 types of succession. Define each.
- Primary
● Primary succession is when life is introduced into a lifeless environment.
This is usually when plants or basic consumers are introduced to a newly
formed area with soil.
- Secondary
● Secondary succession is the change in an ecosystem that already exists
and supports organisms.
3. What do you think is the biggest difference between the two in your own words?
The biggest difference is easily how one occurs. With primary succession, a habitable
land has to have been formed in order to accommodate soil and plants. This is usually a
process that takes millions of years to happen, and might fail to happen. With secondary
succession, the organisms are typically the cause of it. One type of organism might gain
an advantage, or an adaptation might fail to develop, etc.
4. How are whale falls and new life showing up at a hydrothermal vent different in regards
to succession?
Whale falls and hydrothermal vents do not alter an ecosystem but rather create them in
a false sense. This is where organisms simply move to get food.
5. What were the most important things you took from this reading? List at least 5 things
that stood out.
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Only around 200 hydrothermal vents have been discovered, so our information
regarding these and how they work is a little limited and there is still much we
don’t know.
Studies show that life can return to empty ecosystems very fast, shown by the
eruption in 1991 and how fast life returned
Mussels successfully colonized and took over from tube worms, i.e. competition